Development of MSPD method for the determination of pesticide residues in tomato by GC-MS
A simple and effective extraction method based on matrix solid-phase dispersion was developed to determine dimethoate, methyl-parathion, malathion, tebuconazole and cypermethrin in tomato using gas chromatography-mass spectrometry and selected ion monitoring (GC-MS, SIM). Different parameters of the method were evaluated, such as type of solid phase (C18, alumina, sílica-gel and Florisil), the amount of solid phase and eluent [dichloromethane, ethyl acetate, n-hexane and n-hexane:ethyl acetate (1:1 and 1:3, v/v)]. The best results were obtained using 2.0 g of tomato, 0.5 g of alumina as dispersant sorbent, 0.5 g of Florisil as clean-up sorbent and dichloromethane as eluting solvent. The method was validated by fortified tomato samples at different concentration levels (0.05 to 4.0 mg kg-1). Average recoveries (7 replicates) ranged from 77% to 100% with relative standard deviation between 3.7% and 12.9%. Detection and quantification limits ranged from 0.01 to 0.02 mg kg-1 and 0.03 to 0.06 mg kg-1 for the whole fruit of tomato, respectively. The proposed method was applied to analyze of these compounds in commercial tomato samples and residues of methyl-parathion, dimethoate and malathion were detected on the tomato samples at concentrations below the maximum residue levels (MRLs) established by Brazilian legislation and Codex Alimentarius.
| Main Authors: | , , |
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| Format: | Digital revista |
| Language: | English |
| Published: |
Sociedade Brasileira de Química
2006
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| Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000500009 |
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